Started 25mcg 72hr Fentanyl patch and removed it at 40hrs. How long to get out of system?

Mom started 25mcg 72hr Fentanyl patch on Weds 9/18/13 and we removed it after 40hrs because it was too strong. How long before it is out of her system? And how long before she can take an Oxycodone 5/325? She is really out of it and I'm wondering if giving her an Oxycodone might help? Thanks!